Lead pencil



Aug. 13, 1929. B. c. BECKER LEAD PENG IL Filed July ll, 1921 @am s;

Z7 INVLNTOR.

Patented Aug. 13, 1929.

UNTTED STATES PATENT OFFICE.

BERNARD C. BECKER, F ROME, NEW- YORK, ASSIGNOR TO THE YODER PENCL CUM-PANY, 0F CLEVELAND, OHIO, A CORPORATION `Oli' OHIO.

LEAD PENCIL.

Application led July 11,

This invention relates to a lead pencil oli the type wherein the lead issupported in a tubular point and is moved outward by the action ot apush rod.

rlhe object ot this invention is to provide a lead gripping device liorsetting up resistance against lengthwise movement ot the lead,particularly one which can be embodied within a. small slender tube; andturther one which can be arranged to effect a greater or less resistanceto lengthwise movement ot the lead as conditions may require.

A. further object is to provide a pencil ot the character set 'forth onwhich a long slender tubular point may be employed, so that bettervision may be had to the writing. This is accomplished through the smalland compact means which l employ lor pre venting the lead from moving`ahead ot the movement ot the push rod.

lilith these and other objects in view this invention consists ofcertain novel 'features' as hereinafter shown and described, and

then specifically pointed out in the claims.

The practical embodiment ot this invention is represented in theaccompanying drawing forming a part ot this specification, and

in which similar numerals refer to similar parts throughout the severalviews.

Figure l is an elevation of a pencil embodying my invention.

Fig'. 2 is a longitudinal sectional view taken on line 2-2 ot Fig. 1.

Fig. 3 is an enlarged fragmentary view ot the point of the pencil.

Fig. 4 is a longitudinal sectional view of a pencil point. being amodification ot the ioint shown in Fig. 2, at A.

Fig. 5 is a detail view ot the tube B shown in Fig. 4.

Figs. 6, 7 and 8 are enlarged sectional views showing modifications otthe shape of the spiral groove which may be employed in the constructionot the point shown in Fig. 2, at A.

Fig. 9 is a| detail drawing of a part ol' the mechanism tor propelling`the lead.

Fig. l() is a plan view of Fig. 9.

Fig. 11 is a detail drawing ot the end ot' the pencil which holds theeraser.

Figs.y 12, 13 and 14C, represent modifications o't the pointconstruction shown at A, Fig. 2.

With reference to the drawing, l is the resi. serial No. 483,738.

handle of the pencil. 3 is a tubular casing fitting over the end of thehandle l and firmly tixed thereto by solder or otherwise, and inconjunction therewith forms a magazine l tor carrying a surplus store otleads. 5 is an eraser litted into the end of the tubular casing 3, theend ot this casing being threaded as shown at (l, reduced in diameter asshown at 7, and beveled as shown at 8;

short. the same may be extended to proi' trude the original distance byunscrewing the sleeve on the thread (5, thereby releasing the clampingaction ci' the spring ends 11 upon the eraser, after which the erasermay be adjusted as desired and again clamped to hold it lirmly inposition. rThe sleeve 10 is hnurled as shown at 18.

The tubular point A is mounted in the handle 1 at 141- in a manner treeto rotate. ln this tubular point is carried the lead 15 as shown. Fixedto t-he tubular point A or forming a part thereof, are two guide strips16 which guide lengthwise movement ot" the cross head 17 and cause thesame to rotate in unison with the tubular point A. These guide stripsare joined together at the up` per end as shown at 18. rlhe threadedscrew 19 carried by the end 18 ot the guide strips. Between the threadedscrew 19 and the end 18 ot the guide strips is a washer 20. A pin 21 isfitted in the end 18 of the guide strips and through the washer 20, toassure that they both rotate together and prevent loosening the screw19. The washer is carried in the recess 31 ot the handle 1 and terms abearing for the end 18 ot the guide strips.

The cross head 17 is tree to slide between the guide strips 16, andcarries a push rod 22 which is tree to slide in the tubular point A. Thehandle 1 is provided with an internal thread 28 which is adapted toengage with the teeth 24 on the cross head 17. The tubular point A isprovided with a lmurled collar 25.

The operation of this mechanism is as follows: The handle 1 is held inthe right-hand as is natural when writing, and the tubular point A isturned by the left-hand, gripping the same by the knurled collar 25.This causes the cross head 17 to rotate relative to the handle 1 throughthe action of guide strips 16. It is apparent that rotation of the crosshead 17 relative to the handle 1 will cause the same to move lengthwisein the pencil, and carry with it the push rod 22.

his in turn pushes the lead 15 forward in the direction indicated by thearrow 26, and the end 27 ofthe lead may be adjusted to project beyondthe end of the tubular point A as desired.

Vhen the pencil is not in use, the end 27 of the lead may be protectedfrom breaking, by turning the tubular point A in the proper directionfor moving the push rod 22 back into the pencil, after which a slightpressure on the end 27 of the lead will cause the same to move inwarduntil it is liush with the end of tile tubular point A where it issafely protected. y

To avoid the possibilit-y ofthe point A turning accidentally Awhilewriting, l provide a friction device comprising a circular spring 28,normally having a shape as shown in Fig. 10; it is carried in the groove29 which is formed in the washer 20. The end of the spring 28 is bentover and tted into a hole 30 formed in the washer 2O to assure that thespring will rotate therewith. A recess 31 is provided to incase thewasher 20 and spring 28 and the normal tendency of the spring 28 toexpand and accordingly contact with the inner surface thereof willpioduce a resistance to rotation of the tubular point A relative to thehandle 1, due to the friction between the spring 28 and the inner wallof the recess 3 1. By properly proportioning the spring 28 the tubularpoint A will be free enough to be rotated by hand but will not rotateaccidentally.

Referring to Fig. 3 which is an enlarged view of the end of the tubularpoint A shown in Fig. 2. 32 is a spiral spring which is fitted aroundthe lead 1,5 and into the spiral lgroove 33. The normal internaldiameter of the spiral spring 32 is slightly less than the diameter ofthe lead 15, therefore the spiral spring will have a gripping actionupon the lead so that it requires a slight effort 'to slide the lead 15lengthwise through the spiral spring 32. rlhe object of this is toprevent the lead 15 from moving out of the tubular point A ahead of themovement of the push rod 22. A

It is obvious that with this construction any lengthwise movement of thelead 15 will not carry with it the spiral spring 32; for the reason thatthe spiral spring 32 will be held stationary by Ycoming in contact withone of the side walls of the spiral groove 33,

and also the lead 15 may be moved in either direction and will workequally well without causing damage to any of the parts by thisprocedure. 1t is also obvious that the spiral spring 32 produces auniform gripping action all around the lead 15, and that this spiralspring 32 may have a long length, thereby providing a large wearingsurface and long life.

Figs. (i, 7, 8 and 12 show modified shapes of the spiral groove shown atin Fig. 3. Referring to Fig. G, the side walls 34e. of the spiral grooveare inclined. Vhcn in this form and when the lead is moved lengthwise,the spiral spring will wedge itself between one of the side walls andthe surface of the lead 15. This wedging action increases the grippingpressure of the spring 32 on the surface of the lead 15, which in turnincreases the efforts required to move the lead.

. If the side walls of the spiral groove 33 are perpendicular to thesurface of the lead 15 as shown in Fig. 3 at 3G, there is no wedgingaction as above described, and the only el'ort required for moving thelead l5 lengthwise through the spiral spring 32, is that which isnecessary to overcome the inherent gripping action of the spiral spring.

Referring to Fig. 8 in which only one of the side walls of the spiralAgroove is inclined as shown at 34. This construction gives an elliectwhereby the lead may be easily moved lengthwise in one direction, but itwill require more ellfort to move the lead in the opposite direction;this being apparent for the reason that wedging action does not occur onthe spiral spring when the lead is moved in the direction indicated bythe arrow 35; but it does occur when the lead is moved in the oppositedirection, and in the same manner as above described relative to Fig. 6.

Referring to Fig. 7, in which the bottoni surface 37 of the spiralgroove 33 is formed at an angle with the surface of the lead l5. liththis form the results obtained are practically the same as thatdescribed relative to Fig. 8, except that the wedging action et thespring 32 is somewhat greater, because the angle formed by the surfacesbetween which the spring wedges is less; this can readily be seen bycomparing the angle iudicated by 38 to the angle indicated by 39. Thecomparative result obtained by the constructions represented in Figs. 7and 8 is that in both cases the effort required to move the leadlengthwise in the direction indicated by the arrow 35 is the saine, butin the construction shown in Fig. 7 the eilort required to move the leadin the opposite direction will be considerably more than that requiredwith the construction shown in Fig. 8.

t is obvious that with these various lll) shapes for the spiral groove33 or by com# biningsuch shapes to form a spiral groove, the pencil maybe constructed so that the effort required for moving the lead 15lengthwise may be controlled as desired.

A further improvement may be had by consti-noting the spiral spring 32of a wire having a sectional shape substantially the same as the variousshapes shown and described for the spiral groove 33, or more especiallyby making the surface of the spiral spring 82 which comes in contactwith the surface of the lead 15 equal to substantially the full width ofthe spiral groove 33, thereby increasing the wearing surface be` tweenthe spiral spring 32 and the lead 15; this also provides better supportfor the lead 15. One form of this construction is represented in Fig.12, in which the spiral spring 32 is formed of a wire having a squarecross sectional shape to correspond to the shape of the groove 33.

Obviously it is a difficult mattei' to cut a spiral groove like thatshown at E33 in the end of the tubular point A, on account of the holethrough the tubular point necessarily being small to fit the lead. Tofacilitate the forming of the spiral groove 33 in the tubular point A, Iprefer the modified construction as shown in Fig. 4, wherein the tubularpoint A is counterbored as shown to lit the tube B. The end of the tubeB is formed as shown in Fig. which represcnts a tube having an internaldiameter to ht the lead with the wall thereof cut through spirally asindicated by 41. When this tube is placed into the tubular point A asshown in Fig. 4 it produces a spiral in tei-nal groove which ispractically the same as that shown in Fig. 3.

All other matters concerning this invention and which are herein shownand described have the same application with this modified constructionas with the construction shown in Fig. 3.

ln the modified form Fig. 4 the thread 42 is formed on the tubular pointA as shown, and fitted into the knurled collar 25. 43 is a hole intowhich a spanner Wrench may be inserted for unscrewing the tubular pointA from the knurled collar 25, under which conditions the tube B may beremoved, carrying with it the .spiral spring 32.

I have found that, for a simplified construct-ion although not entirelyas satisfactory, the spiral spring 32 may be eliminated; under thiscondition the spiral groove 33 nally becomes lled vwith graphite whichis scraped from the lead by the sharp edge formed by the groove, inconjunction with the wall of the hole; this graphite finally packs insufficiently tight and builds up to an extent whereby it fits neatlyaround the lead, causing suliicient resistance to movenient of the leadand prevents the same from moving ahead of the movement of the push rod22.

It is apparent that under such circumstances it is not necessary thatthe groove 33 should be a spiral, it would then be immaterial whether ornot it comprises a spiral groove or merely a series of circular grooves46 formed around the inside of the wall of the hole, as represented inFig. 14.

Another modified construction would con sist of forming a groove, orseries of grooves around the inside of the hole, and placing therein acontractile spring ring 44, Fig. 13; such ring being preferablyconstructed of wire bent in circular fashion, with its ends abuttingagainst each other; the internal diameter of the ring being sufficientlysmall so it just grips the lead but such ring being yieldable so thatthe lead may be forced through the ring.

The principle involved' in this construction is practically the same asthat wherein the spiral spring 32 is used, t-he difference being merelythat of construction which exists between a wire ring 44 of circularform, and a spiral spring as shown at 32. It is obvious that the sainedifference would necessarily exist between the formation of the grooves,in one form the groove is spiral at 33; in the other it is circular asat 4G.

In manufacturing such construction, it is obvious that substantially thesame scheme may be employed for forming the circular .shaped groove inthe hole, as that shown in Fig. 4, the difference merely being informing the end of the tube B. lt would then not be permissible to cutthe wall of the tube through spirally as shown in Fig. 5, but insteadthe tube should be cut squarely oil'I as shown in Fig. 13, and a seriesof spacing washers 45 should be placed between the wire rings 44; thesespacing washers being arranged to perform the same function as thespirally formed end of the tube B as shown in Fig. 5.

An important feature in connection with this invention is thepossibility of a long slender point; whereby excellent vision may be hadto the writing, and it also provides a means whereby the end of the pushrod 22 may be rapidly adjusted to the location desired. As the pencil isordinarily used it is held in the right hand by the handle 1, and theknurled collar 25 is rotated between the thumb and forelinger of theleft hand for making slight adjustments of the push rod; but when it isdesired to rapidly move the push rod for a considerable distance, forinstance, from an extreme forward position to the extreme rear positionso that a new lead may be inserted into the end of the tubular point A,then such rapid movement accomplished by rotating said tubular.'

- ent, is as follows l. In a lead pencil, the combination of a tubecapable of carrying a lead and having a spiral groove in the materialwhich forms the wall of the hole thereof, and a spiral spring in saidspiral groove.

2. In a lead pencil, the combination of a tube capable of carrying alead and having a spiral groove in the material which forms the wall ofthe hole thereof, and a spiral spring in said spiral groove, said springbeing arranged so that the internal diameter thereof is normally smallerthan said hole, and sufliciently yielding to permit expansion thereofuntil said internal diameter is substantially equal to the diameter ofsaid hole.

3. In a lead pencil, the combination with a tubular point, of a tubewithin said tubular point, the end thereof terminating to a spirallyformed filamentary body arranged to form a spiral groove within saidtubular point, and a spiral spring in said spiral groove.

4. In a lead pencil, the combination with a tubular point, of a spirallyformed filamentary body within said tubular point and arranaged to forma spiral groove, and a spiralspring in said spiral groove.

5. In a lead pencil, the combination of a tube capable of carrying alead, a spiral groove in said tube, and a spiral spring in said groove,said spring being arranged to wedge between the wall of Said groove andthe surface of said lead when said lead is moved lengthwise in saidtube.

6. In a lead pencil, the combination of a tube, a spiral groove in saidtube, a push rod adapted to move lengthwise in said tube, and a spiralspring in said groove, said spring being arranged to wedge between thewall of said groove and the surface of said push rod when said push rodis moved lengthwise in said tube.

7. In a lead pencil, the combination of a tube capable of carrying alead and having a groove in the material which forms the wall of thehole thereof, one wall of said groove being at an angle with the surfaceof said lead, and a contractile spring in said groove, said spring beingarranged to wedge between said angular wall and the surface of said leadwhen said lead is moved lengthwise in said tube.

8. In a lead pencil, the combination of a tube for supporting a lead andformed on its inner wall with a groove, one wall of said groove being atan angle with the central axis of said hole, a push rod adapted to movelengthwise in said tube, and a contractile spring in said groove, saidspring being arranged to wedge between said angular wall and the surfaceof the lead and said push rod when said push rod is moved lengthwise insaid tube.

9. A lead pencil point comprising a lead carrying tube suitable forguiding the lead through lengthwise movement and having a groove in thematerial which forms the wall of the hole thereof, said groove beingarranged to circumscribe said hole.

l0. In a lead pencil, the combination of a tube capable of carrying alead and having a groove in the material which forms the wall of thehole thereof, said groove being arranged to circumscribe said hole, anda contractile spring in said groove, said spring being arranged so thatthe internal diameter thereof is normally smaller than said hole, andsufficiently yielding to permit expansion thereof until said internaldiameter is substantially equal to the diameter of said hole.

ll. In a lead pencil, the combination of a tube capable of carrying alead and having a groove in the material which forms the wall of thehole thereof, and a contractile spring in said groove.

12. In a lead pencil point, the combination of a tube for receiving alead and having an internal spiral groove, and means in the spiralgroove for retarding movement of the lead through the tube.

In testimony whereof I have signed my name to this specification.

BERNARD C. BECKER.

